Lock for machine-screws.



i UltllTED @la WlLLlAlvl SCHOTT, OF ST. LOUIS, MISSOURI.

LOCK EUR IVIACHINE-SCREWS.

no. season.

To @ZZ who/m 'it may concern.'

le it irnowi 'hat l, tif/Imran Sonora?, citit Zen ollv the Unit dStates, residing at St. Louis, State ot ssouri, have invented certainnew and useful improvements in lioclis tor laaoliinaScreu/s, of whichthe following is a specification.

The purpose of' this invention is to prevent the loosening of woodscrews, the saine innig oll advant ge in bridge building and otherstructures formed ol wooden timbers and united by inoans of lag or woodscrews.

in accordance with this invention a lock is provided and arranged tocooperate with the Ausual wood screw to torni positive securing meanstherefor against backward rotation, said loch consisting of asubstantially llat spring having an approximate tangential arrangementto the head of the screw and located so as to engage the slot formed insaid head to receive the screw driver, said spring being arranged in agroove torined in the material at one side of the opening in which thescrew is fitted. u

For a lull understanding of the invention and tho rnerits thereoi1 andalso to acquire a knowledge oi the details olI construction and themeans for etlecting the result, reference is to be had to the followingdescription and accoinnanying drawings, in which:

Figure l is a perspective view showing the application of the invention;Fig. 2 is plan or end view 3 and, Fig. 3 is a detail view.

Corresponding and like parts are referred to in the followingdescription and indicated in all the views olI the drawings by the sainereference characters.

lfhe screw illustrated is ot ordinary l'orni commonly provided i'orjoining parts to be connected and is supplied in its head with the usualtransverse slot l to receive the screw driver. ln accordance with thisinvention a loch 2 is ,or'ovicled, the saire consisting ol' asubstantially 'flat spring arranged in a groove or channel 3 provided inthe work or material at one side oil the opening through which the screw4 is passed when in position. The flat spring 2 is provided with abeveled extremity l'or engagement with the head oi' the screw at the endol the slot l formed therein. lhe groove or channel 3 has asubstantially tangential arrangement with reference to the head or bodyof the screw, so that the adja K cent end oll the lock 2 inay engagewith one side ol' the slot 1 and thereby prevent bachward rotation orloosening ol the screw.

Specification of Letters Patent.

Application filed January 2, 1909.

Patented May 4, 1909.

Serial No. 'TOGi.

rlhe tangential arrangement of the loch 2 ad niits ol' the forwardrotation ol' the screw when driving the saine honie. rThe groove orchannel 3 inay be provided in any inanner and is ol" such size as toretain the loch spring 2 in place and yet adinit ol' the end portion ol'the locl` adjacent to the screw having a limited niov nient, so as toclear the screw and vet react and engage with a side ol' the slot l, soas to secure the screw against backward inovenient.

lt will be understood troni the Yforegoing that the invention providessiinple an d eil'ect* ive ineans lor securing wood screws ot' ordinaryconstruction without necessitating any .change or inodi'lication intheir l'orination,

hence the invention inay be readily applied to wood screws as coininonlyinainrlactured and in general use. The groove or channel 3 inay beiorred in any inanner so as to provide a seat in which the loch 2 isfitted. The approximate tangential arrangement oi the spring isnecessary to perinit the forward rotation ci the screw and yet securethe saine l'roni loosening.

Vilhile the invention is described in connec tion with a wood screw itis not to be restricted in its use and may be applied to niachine screwsor analogous tastenings having slotted heads, so as to secure the sainei'ronr turning backward alter being tightened.

Having thus described the invention what is claimed as new is:

ln a screw lock as speciiied, the combination ol' a screw having a slotl'ornicd in the head thereof, said screw positioned through a piece ofworl, ot' a tlat spring being arranged edge-wise in the worh intangential relation i to the head of said screw said s )rine bein@ Q Cenlarged at its inner end to i'orin an abutnient to hold the saineiirinly in the work, the slot in the work l'or the reception ol' saidspring being ol uniform width throughout to admit oli' the vibration olthe forward end oll said spring when said screw is rotated. lorwardly,and having a beveled outer end to engage one wall ot the slot in thehead oi saidv screw to prevent the backward rotation ol the saine.

ln testiniony whereof l atlix .my signature in presence oll twowitnesses.

WlLLlAt/l SCllYlI.

ll-itnesses Josnrn LAMMnnT, .learns lt'lanonv.

